A leading trade union and a charity joined forces yesterday to accuse the Government of launching an "assault" on the poorest members of society in its response to the state of the economy.

The GMB and War on Want said the UK, and other world leaders meeting at the G20 summit in Cannes this week, should abandon the "neoliberal" economic model they claimed led to the worst recession in 80 years.

The two organisations criticised deregulation and the pursuit of free trade, saying multinational corporations had been able to maximise profits by driving down workers' pay and conditions and "decimating" job security.

GMB general secretary Paul Kenny said: "The current economic model is driven by growth and the accumulation of capital, often to the exclusion of all other objectives.

War on Want executive director John Hilary said: "From Wall Street to St Paul's, from the streets of Athens to Tahrir Square, a growing movement is calling for an end to a system based on financial bubbles and corporate greed.

"If David Cameron and the G20 leaders want to remain relevant in the 21st century, they should drop their obsession with free markets and listen to their citizens."